This invention relates to frequency measurement. Frequency measurement of an incoming signal is required in a number of circumstances, for example for measuring the centre frequency of radio and microwave signals.
Known methods of frequency measurement include the use of pulse counting, as described for example in UK Paten Application GB NO. 2196497A. An alternative method of frequency measurement involves the use of transformation techniques for transferring between the time domain to the frequency domain, as described for example in U.S. Pat. No. 4,743,905.
Such known methods suffer the disadvantage however that they require comparatively long sampling of the input signal.